Improvement in torpedoes for oil-wells



LA. L. ROBERTS. Improvement in Torpedoes for Oil WeHs.

Patented Jan. 9, 1872.

'3 mrmwm EDWARD A. L. ROBERTS, OF TITUSVILLE, PENNSYLVANIA.

IMPROVEMENT IN TORPEDOES FOR OIL-WELLS.

Specification forming part of Letters Patent No. 122,654, dated January 9, 1872.

To all whom it may concern:

Be it known that I, EDWARD A. L. ROBERTS, of Titusville, in the county of Crawford and State of Pennsylvania, have invented a new and useful Improvement in Torpcdoes for Oil- VVells; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawing making a part of this specification, which represents a longitudinal sectional view of my improved torpedo.

The use of torpedoes for increasing the productiveness of oil-wells has of late years been extensively resorted to. In such use it is de sirable not only that the torpedo be exploded in that part of the rockthat yields the oil, but also that some tampiug be employed immediately above the torpedo for confining the effect of the explosion as completely as may be, to the walls of that part of the well at which the torpedo is exploded. The difficulty of employing the mode of tamping ordinarily used in dry blasting is too obvious to require explanation. The use of a fluid tamping is set forth in Letters Patent granted to me November 20, 1866. In what are commonly known as cased wells it is usual to torpedo the wells withoutremoviu g the casin g, and in many such cases it is necessary to run fluid into the wells mouth in order to secure a proper fluid tamping. For use in such wells, especially when, as is sometimes the case, water or benzine is not easily obtainable, I have devised a torpedo which is made with a tamping-charge at its upper part, of sand, shot, or other smallgrained substance, wet or dry. The explosive substance or compound occupies the lower part of the torpedo, and the firing apparatus is arranged at any suitable point relatively to the explosive charge where it will secure ignition and explosion.

To enable others skilled in the art to make and use my improvement, I will proceed to describe its construction and mode of operation.

The torpedo-case or shell bis made of any suitable material and of sufficient length to contain in its upper end a tamping-charge, g, represented by dots, as large as may be desired, of sand, shot, or other small-grained substance of considerable gravity, wet or dry preferably the former. The lower part, f, of

the case is charged with powder, nitro-glycerine, dualine, or other suitable explosive substance or compound; and if one be wet and the other dry, or if the explosive charge be liquid while the tampin g-charge is not, the two charges should be separated by a diaphragm, b which divides the torpedo-case into two chambers-the upper one a tamping-chamber and the lower one a blasting-chamber. I prefer to use a diaphragm in all cases, though,

except under the above-named circumstances, its presence is not essential. The tampingcharge, instead of being of a granular or granulated substance, may be solidsuch as would be made of stone or of plaster of Paris mixed with water or other fluid.

Many forms of firing apparatus may be employed to ignite the explosive charge in the torpedo described, the one shown in the drawing being, in most respects, substantially that shown and described in Letters Patent granted to me April 25, 1865, except that instead of employing a falling weight I drop the torpedo into the well and the fluid contents of the well having been pumped down to ornea-r to a level with the oil-bearing rock, the impact of a falling torpedo on the surface of the oil or water in the well causes the explosion.

The priming-chamber a is of the construction described in the patent last referred to,

though, relatively to the explosive charge, it is inverted. a is the cork or plug that closes the mouth of the priming-chamber. c is the gun-nipple or anvil, on which is placed a percussion-cap or fulmin ate. a istheguard, which extends up around the nipple c. d is the bolt or mandrel by which the cap or fulminate is exploded, and e is the India-rubber tube that packs the joint. The lower end of the bolt or mandrel d terminates in a disk, or preferably an inverted cup, 61', which, striking the water, causes the explosion of the charge. The lower end of the torpedo-shell projects sufficiently far to keep the disk d from striking the sides of the well as the torpedo goes down 5; or, as shown, a guard-tube, b may be inserted for that purpose.

To secure the more perfect ignition of the explosive charge when a dry or non-fluid explosive is used I extend from the priming-chamber a, up through the blastingchamber, a tube,

a, made of tin or other suitable material. This tamping above confines the effect of the extube has a series of perforations. 8, many desired number or order, over which I paste a light covering of paper, 8, cloth, or other material which is easily broken. In connection with such a perforated tube I use a metal plug, 00 in the mouth of the priming-cl1amber a. The papers covering the perforations s keeps the powder or other explosive material from entering the tube n. Then, when the torpedo, falling by its own weight, strikes the water, the bolt 01 explodes the cap on the nipple c. This ignites the explosive charge in the priming-chamber a, and, by its explosion, the metal plug a is projected like a bullet up the tube n, whereby the covering on the perforations s is ruptured, and the main charge is ignited at each perforation. From each perforation the fire burns outwardly, and spreads so as to ignite the largest possible amount of the explosive material. In this way the main charge of the torpedo is exploded. But, if the tube at be not used, the explosion of the priming-charge projects a column of flame, heated gases, 850., up into and through the main torpedocharge, thus exploding it. In either case the non-fluid plosion to the Walls of the well immediately adjacent, with the usual beneficial result. But I do not confine myself to any particularmode of firing the torpedo, as, instead of being dropped,

it may be lowered from the top in the usual way and fired by means of electricity, frictionprimer, or other means known to the art.

I am aware that a wooden plug has been attached to the upper end of an ordinary blasting-charge, as described in English patent to H. and E. Sutherland, No. 2,816, of 1864; and such device, constructed as therein set forth, I hereby disclaim.

What I claim as my invention, and desire to secure by Letters Patent, is-

A torpedo-case for oil and other deep wells inclosin g a non-fluid tamping-charge in its upper end above the explosive charge, substantially as described.

In testimony whereof I, the said EDWARD A. L. ROBERTS, have hereunto set my hand.

EDWARD A. L. ROBERTS.

Witnesses:

A. S. NIcHoLsoN,

G. H. OHRIsrY. (124) 

